Large-scale transferable flexible UV detectors enabled by h-BN release layers

The fabrication of flexible optoelectronic devices presents challenges due to thin-film transfer, epitaxial growth, and other factors. This study demonstrates the fabrication of wafer-scale flexible ultraviolet photodetectors (UV PDs) based on AlGaN/GaN heterostructures, using hexagonal boron nitride (h-BN) as a release layer and bonding-assisted transfer techniques. We systematically investigated the role of h-BN thickness in stress relaxation and delamination during the transfer process, revealing that an optimal thickness of 3 nm ensures efficient wafer-level transfer without compromising device quality. The resulting flexible UV PDs exhibit excellent performance, including a detectivity of 1.66 × 10 12 Jones, a responsivity of 149.5 A/W, enhanced response times, and significantly reduced persistent photoconductivity (PPC) effects at 100°C. These results highlight the potential of h-BN as a critical release layer in scalable fabrication, enabling high-performance flexible optoelectronic devices for applications in extreme thermal environments.